In part one of the study, each subject will provide a saliva sample. DNA will be isolated, purified, and quantitated for alleles of TAS2R38, a bitter taste receptor gene. Based on the results of the genetic screen, 25 individuals with the heterozygous genotype will be invited to return for part two of the study. In part two of the study, subject will provide nasal epithelium and taste tissue in the form of fungiform papillae. One half of each set of tissue will be placed in saline on ice in preparation for cell culture and assessment of AHL-induced defensive responses, while the second half will be placed in RNA preservative for mRNA isolation.